In the construction of crankshafts, it is common practice to form them in one piece by machining bar stock or forgings or castings and also, but to less extent, to fabricate them with an assemblage of one or more crank lobes and shaft parts. With the former approach, the fact that there is eccentricity can lead to both manufacturing and performance problems. For example, considerable machining is normally required when making the crankshaft from barstock and special patterns and dies are required with castings and forgings. Moreover, expensive specialized machine tooling is required whether bar stock, castings or forgings are used. In addition, it is difficult to hold tight tolerances since the part is not balanced when rotated during machining. On the other hand, with a fabricated crankshaft, there is the difficulty in accurately assembling and holding the crank lobes on the shaft. Furthermore, all the above crankshafts are not inherently balanced and as a result can shorten bearing life or require the use of a counterbalance.